Cation Distribution by Powder X-Ray Diffraction in Uvarovite-Grossularite Garnets Solid Solutions Synthesized by the Sol-Gel Method

Abstract

Nominal compositions of uvarovite-grossularite solid-solutions Ca 3(Cr 1- x Al x ) 2Si 3O 12, series x = 0 to x = 1, have been prepared by sol-gel method and fired up to 1000°C. Five of these structures ( x = 0 to 0.5) have been refined using the Rietveld method from X-ray powder diffraction data taken with a Siemens D-500 diffractometer. The limit of solid solutions of these structures has been stabilized in 20% mole grossularite. The unit cell is cubic, Ia3d (230), Z = 8, a = 12.0205(5) to 11.9903(18) for the five structures presented.